大多数集合都在System.Collections，System.Collections.Generic两个命名空间。其中System.Collections.Generic专门用于泛型集合。
针对特定类型的集合类型位于System.Collections.Specialized;命名空间；
线程安全的集合类位于System.Collections.Concurrent;命名空间。
下面是集合和列表实现的接口如下：
一、列表
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(Mscorlib_CollectionDebugView<>))]
[DebuggerDisplay("Count = {Count}")]
public class List<T> : IList<T>, ICollection<T>, IEnumerable<T>, IList, ICollection, IEnumerable
从这个可以看出，泛型集合List<T>实现了这么多接口，具体接口的信息可以通过工具查看。
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
List<String> list = new List<string>();
list.Add("张三");
list.Add("李四");
list.Add("王五");
list.Add("田六");
list.Add("赵七");
for (int i = 0; i < list.Count; i++)
{
Console.WriteLine("for循环：" + i.ToString() + "=" + list[i]);
}
list.RemoveAt(0);
foreach (String item in list)
{
Console.WriteLine("foreach迭代：" + item);
}
list.AddRange(new String[] { "Hello1", "Hello2", "Hello3" });
list.ForEach(Print);
Console.Read();
}
private static void Print(String item)
{
Console.WriteLine("ForEach：" + item);
}
}
}
二、队列
队列先进先出，一头进一头出，用Queue<T>实现
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(System_QueueDebugView<>))]
[ComVisible(false)]
[DebuggerDisplay("Count = {Count}")]
public class Queue<T> : IEnumerable<T>, ICollection, IEnumerable
可以看出队列实现了集合的接口，迭代的接口
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
Queue<String> queue = new Queue<string>();
//进队
queue.Enqueue("张三");
queue.Enqueue("李四");
queue.Enqueue("王五");
queue.Enqueue("田六");
queue.Enqueue("赵七");
foreach (String item in queue)
{
Console.WriteLine("foreach迭代：" + item);
}
//出队
while (queue.Count > 0)
{
Console.WriteLine("出队：" + queue.Dequeue());
}
Console.Read();
}
}
}
三、栈
栈：从同一边先进后出，用Stack<T>实现
[csharp]
view plain copy[DebuggerDisplay("Count = {Count}")]
[DebuggerTypeProxy(typeof(System_StackDebugView<>))]
[ComVisible(false)]
public class Stack<T> : IEnumerable<T>, ICollection, IEnumerable
栈也是实现了集合接口与迭代接口的
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
Stack<String> stack = new Stack<string>();
//进栈
stack.Push("张三");
stack.Push("李四");
stack.Push("王五");
stack.Push("田六");
stack.Push("赵七");
foreach (String item in stack)
{
Console.WriteLine("foreach迭代：" + item);
}
//出栈
while (stack.Count > 0)
{
Console.WriteLine("出栈：" + stack.Pop());
}
Console.Read();
}
}
}
四、链表
LinkedList是一个双向链表，链表有个有点，就是在链表中间插入、删除元素很快，但是查找中间与末尾的元素很慢，需要一个节点一个节点的去找。
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(System_CollectionDebugView<>))]
[DebuggerDisplay("Count = {Count}")]
[ComVisible(false)]
public class LinkedList<T> : ICollection<T>, IEnumerable<T>, ICollection, IEnumerable, ISerializable, IDeserializationCallback
由此可见链表也是有集合的特性的，可以迭代，同时还有链表的特性
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
LinkedList<String> lList = new LinkedList<string>();
LinkedListNode<String> node = new LinkedListNode<string>("root");
lList.AddFirst(node);
node = lList.AddAfter(node, "张三");
node = lList.AddAfter(node, "李四");
node = lList.AddAfter(node, "王五");
node = lList.AddAfter(node, "田六");
node = lList.AddAfter(node, "赵七");
foreach (String item in lList)
{
Console.WriteLine("foreach迭代：" + item);
}
node = lList.First;
Console.WriteLine("第一个元素：" + node.Value);
node = lList.Last;
Console.WriteLine("最后一个元素：" + node.Value);
Console.Read();
}
}
}
五、有序列表
SortedList采用键-值对存储，键不能重复，并且会根据key进行排序
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(System_DictionaryDebugView<,>))]
[DebuggerDisplay("Count = {Count}")]
[ComVisible(false)]
public class SortedList<TKey, TValue> : IDictionary<TKey, TValue>, ICollection<KeyValuePair<TKey, TValue>>, IEnumerable<KeyValuePair<TKey, TValue>>, IDictionary, ICollection, IEnumerable
可以看出SortedList不仅具有字典的特性，还有集合，迭代的功能
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
//Key必须唯一，如果不唯一可以考虑Lookup<TKey,TElement>
SortedList<int, String> sList = new SortedList<int, string>();
sList.Add(100, "张三");
sList.Add(21, "李四");
sList.Add(13, "王五");
sList.Add(44, "田六");
sList.Add(35, "赵七");
foreach (KeyValuePair<int, String> item in sList)
{
Console.WriteLine("key=" + item.Key.ToString() + "；value=" + item.Value);
}
Console.Read();
}
}
}
六、字典
字典是很复杂的
数据结构，允许通过key来查找值，字典可以自由添加、删除元素，没有集合由于移动元素导致的开销。
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(Mscorlib_DictionaryDebugView<,>))]
[DebuggerDisplay("Count = {Count}")]
[ComVisible(false)]
public class Dictionary<TKey, TValue> : IDictionary<TKey, TValue>, ICollection<KeyValuePair<TKey, TValue>>, IEnumerable<KeyValuePair<TKey, TValue>>, IDictionary, ICollection, IEnumerable, ISerializable, IDeserializationCallback
可以看出字典也具有集合的特性，可以迭代
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
//Key必须唯一
Dictionary<int, String> dict = new Dictionary<int, string>();
dict.Add(11, "张三");
dict.Add(1, "李四");
dict.Add(2, "王五");
dict.Add(16, "田六");
dict.Add(12, "赵七");
foreach (KeyValuePair<int, String> item in dict)
{
Console.WriteLine("key=" + item.Key.ToString() + "；value=" + item.Value);
}
Console.Read();
}
}
}
说到字典，顺便谈一下有序字典，与有序列表对应；SortedDictionary，SortedList，SortedSet
会根据Key进行排序
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
//Key必须唯一
SortedDictionary<int, String> dict = new SortedDictionary<int, string>();
dict.Add(11, "张三");
dict.Add(1, "李四");
dict.Add(2, "王五");
dict.Add(16, "田六");
dict.Add(12, "赵七");
foreach (KeyValuePair<int, String> item in dict)
{
Console.WriteLine("key=" + item.Key.ToString() + "；value=" + item.Value);
}
Console.Read();
}
}
}
七、集
集(Set)：包含不重复元素，常用HashSet，SortedSet
[csharp]
view plain copy[Serializable]
[DebuggerDisplay("Count = {Count}")]
[DebuggerTypeProxy(typeof(HashSetDebugView<>))]
public class HashSet<T> : ISerializable, IDeserializationCallback, ISet<T>, ICollection<T>, IEnumerable<T>, IEnumerable
[csharp]
view plain copy[Serializable]
[DebuggerTypeProxy(typeof(SortedSetDebugView<>))]
[DebuggerDisplay("Count = {Count}")]
public class SortedSet<T> : ISet<T>, ICollection<T>, IEnumerable<T>, ICollection, IEnumerable, ISerializable, IDeserializationCallback
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
HashSet<String> hSet = new HashSet<string>();
hSet.Add("张三");
hSet.Add("李四");
hSet.Add("王五");
hSet.Add("田六");
hSet.Add("赵七");
foreach (String item in hSet)
{
Console.WriteLine("foreach迭代：" + item);
}
Console.Read();
}
}
}
[csharp]
view plain copyusing System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
public class Program
{
static void Main(string[] args)
{
SortedSet<String> hSet = new SortedSet<string>();
hSet.Add("张三");
hSet.Add("李四");
hSet.Add("王五");
hSet.Add("田六");
hSet.Add("赵七");
foreach (String item in hSet)
{
Console.WriteLine("foreach迭代：" + item);
}
Console.Read();
}
}
}
性能比较：
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